A treatise on forest-trees

The fad for tree calf, or tree marble, is an excellent example of the fleeting nature of style. For about 150 years (1775-1920), tree calf was among the most popular forms of cover illustration; then it disappeared.

Tree calf is created by allowing water to run down the center of a calfskin cover to form the tree’s “trunk,” and then out into “branches” towards each side. While the water is still running, copperas and potassium sulfate are applied: the resulting chemical reaction etches the image of a tree onto the leather.

In a collection with strong holdings on botany and dendrology, tree calf bindings are especially evocative. But, just as floral decoration could grace the binding of any number of books, tree calf is by no means exclusive to books about plants or trees.